Strep-CaDI: A fast, accurate, and sensitive point-of-care test for Group A Streptococcus

Strep-CaDI：快速、准确且灵敏的 A 组链球菌现场检测

• 批准号: 10699852
• 负责人: Zachary David Call
• 金额: $ 27.96万
• 依托单位: BURST DIAGNOSTICS LLC
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10699852
• 关键词: 2019-nCoV; 3D Print; Antibiotic Therapy; Antibiotics; Antibodies; Antigens; Antimicrobial Resistance; Bacteria; Biological Assay; Blood capillaries; Buffers; COVID-19 outbreak; Child; Clinic; Clinical; Colorado; Communicable Diseases; Detection; Development; Device Designs; Devices; Diagnostic; Diagnostic Procedure; Disease; Dose; Enzyme-Linked Immunosorbent Assay; Evaluation; Exposure to; Feedback; Film; Funding; Future; Generations; Goals; Health Personnel; Home; Housing; Human Resources; Immunoassay; Individual; Infection; Infrastructure; Injections; Kinetics; Label; Laboratories; Legal patent; Manuals; Marketing; Methods; Microfluidic Microchips; Microfluidics; Modeling; Molds; Molecular; Outcome; Paper; Patient Care; Patients; Penetration; Performance; Pharyngeal structure; Pharyngitis; Physicians; Polyesters; Procedures; Protocols documentation; Pump; RADx; Rapid diagnostics; Reaction; Reading; Reagent; Reporting; Running; SARS-CoV-2 antigen; Sampling; Sensitivity and Specificity; Series; Signal Transduction; Sore Throat; Speed; Streptococcus pyogenes; Swab; Symptoms; System; Technology; Telemedicine; Test Result; Testing; Time; Training; Treatment Protocols; United States National Institutes of Health; Universities; Work; accurate diagnosis; acute symptom; antigen detection; cost; design; detection limit; detection test; gut microbiome; home test; hydrophilicity; improved; instrumentation; manufacture; nanoparticle; operation; phase 2 study; physical symptom; point of care; point of care testing; point-of-care diagnostics; preservation; prototype; rapid test; rural health clinic; screening; stem

SUMMARY The current rapid antigen detection tests for group A strep lack sensitivity and result in upwards of 10 million unnecessary antibiotic treatments provided to children each year. Current diagnostic methods utilized when a patient presents at a clinic with a sore throat include a throat swab and rapid strep test. A positive rapid test results in antibiotic prescription, but due to the low sensitivity of existing rapid strep immunoassays, physicians often prescribe antibiotics as a precaution while waiting for culture results after a negative rapid test. It is estimated that up to 70% of these doses are unnecessary, contributing to the rise in antimicrobial resistance. While ELISAs and molecular (PCR-based) assays with improved sensitivity have been reported to reduce unnecessary antibiotic treatment, these tests rely on laboratory instrumentation and significant infrastructure, making them unsuitable for point-of-care settings and rural clinics, and impossible to implement as at-home testing protocols for telemedicine purposes. Thus, there is an urgent unmet need for an improved, ultrasensitive rapid strep test that could reduce the unnecessary use of antibiotics, stemming the increase in antimicrobial resistance and preserving the gut microbiome of children. Furthermore, if an improved rapid strep test could be optimized for robustness and ease of use, as well as sensitivity, it could be performed at home enabling telemedicine protocols and reducing the need for a potentially infected individual to expose frontline healthcare workers. The outcome of this project will be a proof-of- principle demonstration of an ultrasensitive rapid strep test with onboard reagents that requires a simple swab insertion step to initiate to completion with limits of detection 10-100x lower than current dipstick methods. Improved sensitivity will be achieved through use of the Capillary-Driven Immunoassay (CaDI) technology in which we are able to integrate all steps of highly sensitive, laboratory-performed ELISAs (washing, labeling, and amplification) on a simple microfluidic device without requiring instrumentation or highly trained personnel. This first-in-its-class microfluidic point-of-care (POC) device will be realized through the following aims. First, proof of concept for a Strep-CaDI rapid strep test will be demonstrated for the ultrasensitive detection of Streptococcus pyogenes antigen in spiked buffer through antibody screening and assay parameter optimization. Secondly, the bacterial extraction method and corresponding CaDI parameters and device design will be optimized for use with clinical samples spiked with whole bacteria. The final, optimized design will be compared to current market solutions to compare assay sensitivity (LOD), time to result, and complexity (steps to result). Lastly, to increase the likelihood of approval for at-home use and to provide a clear market advantage over current solutions, we will prototype (through modeling, 3D printing, and testing) an assay housing capable of simplifying CaDI operation to a simple swab->insert-> read mechanism which initiates the assay to completion and isolates all reagents from the operator. Once the required functionality is achieved, the housing and immunoassay will be tested by untrained individuals. Feedback from these trials will be used for housing design iterations. Completion of these three aims will result in a prototype rapid strep test with the ease-of-use of a simple dipstick test and the sensitivity of a laboratory ELISA.

概括 目前针对 A 组链球菌的快速抗原检测缺乏敏感性，导致超过 1000 万次不必要的检测 每年为儿童提供抗生素治疗。患者到诊所时使用的当前诊断方法 喉咙痛包括咽拭子和快速链球菌测试。抗生素处方中快速检测结果呈阳性，但由于 由于现有快速链球菌免疫测定的灵敏度较低，医生经常开抗生素作为预防措施，同时 快速检测呈阴性后等待培养结果。据估计，其中高达 70% 的剂量是不必要的， 导致抗菌素耐药性上升。虽然 ELISA 和分子（基于 PCR）检测具有改进 据报道，敏感性可以减少不必要的抗生素治疗，这些测试依赖于实验室仪器和 重要的基础设施，使其不适合护理点环境和农村诊所，并且无法实施 作为用于远程医疗目的的家庭测试协议。因此，迫切需要一种改进的、超灵敏的 快速链球菌检测可以减少抗生素的不必要使用，阻止抗菌素耐药性的增加， 保护儿童肠道微生物群。此外，如果改进的快速链球菌测试可以优化稳健性 且易于使用以及灵敏度高，可以在家中进行，从而实现远程医疗协议并减少需求 让潜在感染者暴露一线医护人员。该项目的结果将证明- 使用机载试剂进行超灵敏快速链球菌测试的原理演示，只需简单的拭子插入步骤 从开始到完成，检测限比当前量油尺方法低 10-100 倍。灵敏度将会提高 通过使用毛细管驱动免疫测定 (CaDI) 技术实现，我们能够整合所有步骤 在简单的微流体装置上进行高灵敏度、实验室执行的 ELISA（清洗、标记和扩增） 无需仪器或训练有素的人员。这款同类首创的微流控护理点 (POC) 设备 将通过以下目标来实现。首先，将展示 Strep-CaDI 快速链球菌检测的概念验证 通过抗体筛选和测定，超灵敏地检测加标缓冲液中的化脓性链球菌抗原 参数优化。其次，细菌提取方法及相应的CaDI参数及装置设计 将针对掺有全细菌的临床样品进行优化。最终的优化设计将与 当前市场解决方案用于比较检测灵敏度 (LOD)、获得结果的时间和复杂性（获得结果的步骤）。最后，为了 增加批准在家使用的可能性并提供比当前解决方案明显的市场优势，我们将 原型（通过建模、3D 打印和测试）能够将 CaDI 操作简化为简单的分析外壳 拭子->插入->读取机制启动测定直至完成并将所有试剂与操作员隔离。一次 实现所需的功能后，外壳和免疫测定将由未经培训的人员进行测试。反馈来自 这些试验将用于住房设计迭代。完成这三个目标将产生快速链球菌原型 具有简单试纸测试的易用性和实验室 ELISA 的灵敏度。